From: Oleksandr Andrushchenko <oleksandr_andrushche...@epam.com>
Assign SBDF to the PCI devices being passed through with bus 0.
The resulting topology is where PCIe devices reside on the bus 0 of the
root complex itself (embedded endpoints).
This implementation is limited to 32 devices which are allowed on
a single PCI bus.
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushche...@epam.com>
---
New in v2
---
xen/common/domain.c | 1 +
xen/drivers/passthrough/pci.c | 57 +++++++++++++++++++++++++++++++++++
xen/drivers/vpci/vpci.c | 18 +++++++++--
xen/include/xen/pci.h | 18 +++++++++++
xen/include/xen/sched.h | 6 ++++
5 files changed, 97 insertions(+), 3 deletions(-)
diff --git a/xen/common/domain.c b/xen/common/domain.c
index 40d67ec34232..b80ff2e5e2e6 100644
--- a/xen/common/domain.c
+++ b/xen/common/domain.c
@@ -601,6 +601,7 @@ struct domain *domain_create(domid_t domid,
#ifdef CONFIG_HAS_PCI
INIT_LIST_HEAD(&d->pdev_list);
+ INIT_LIST_HEAD(&d->vdev_list);
#endif
/* All error paths can depend on the above setup. */
diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c
index e1da283d73ad..4552ace855e0 100644
--- a/xen/drivers/passthrough/pci.c
+++ b/xen/drivers/passthrough/pci.c
@@ -833,6 +833,63 @@ int pci_remove_device(u16 seg, u8 bus, u8 devfn)
return ret;
}
+static struct vpci_dev *pci_find_virtual_device(const struct domain *d,
+ const struct pci_dev *pdev)
+{
+ struct vpci_dev *vdev;
+
+ list_for_each_entry ( vdev, &d->vdev_list, list )
+ if ( vdev->pdev == pdev )
+ return vdev;
+ return NULL;
+}
+
+int pci_add_virtual_device(struct domain *d, const struct pci_dev *pdev)
+{
+ struct vpci_dev *vdev;
+
+ ASSERT(!pci_find_virtual_device(d, pdev));
+
+ /* Each PCI bus supports 32 devices/slots at max. */
+ if ( d->vpci_dev_next > 31 )
+ return -ENOSPC;
+
+ vdev = xzalloc(struct vpci_dev);
+ if ( !vdev )
+ return -ENOMEM;
+
+ /* We emulate a single host bridge for the guest, so segment is always 0.
*/
+ *(u16*) &vdev->seg = 0;
+ /*
+ * The bus number is set to 0, so virtual devices are seen
+ * as embedded endpoints behind the root complex.
+ */
+ *((u8*) &vdev->bus) = 0;
+ *((u8*) &vdev->devfn) = PCI_DEVFN(d->vpci_dev_next++, 0);
+
+ vdev->pdev = pdev;
+ vdev->domain = d;
+
+ pcidevs_lock();
+ list_add_tail(&vdev->list, &d->vdev_list);
+ pcidevs_unlock();
+
+ return 0;
+}
+
+int pci_remove_virtual_device(struct domain *d, const struct pci_dev *pdev)
+{
+ struct vpci_dev *vdev;
+
+ pcidevs_lock();
+ vdev = pci_find_virtual_device(d, pdev);
+ if ( vdev )
+ list_del(&vdev->list);
+ pcidevs_unlock();
+ xfree(vdev);
+ return 0;
+}
+
/* Caller should hold the pcidevs_lock */
static int deassign_device(struct domain *d, uint16_t seg, uint8_t bus,
uint8_t devfn)
diff --git a/xen/drivers/vpci/vpci.c b/xen/drivers/vpci/vpci.c
index 0cdc0c3f75c4..a40a138a14f7 100644
--- a/xen/drivers/vpci/vpci.c
+++ b/xen/drivers/vpci/vpci.c
@@ -90,24 +90,36 @@ int __hwdom_init vpci_add_handlers(struct pci_dev *pdev)
/* Notify vPCI that device is assigned to guest. */
int vpci_assign_device(struct domain *d, const struct pci_dev *dev)
{
+#ifdef CONFIG_HAS_VPCI_GUEST_SUPPORT
+ int rc;
+#endif
+
/* It only makes sense to assign for hwdom or guest domain. */
if ( is_system_domain(d) || !has_vpci(d) )
return 0;
#ifdef CONFIG_HAS_VPCI_GUEST_SUPPORT
- return vpci_bar_add_handlers(d, dev);
-#else
- return 0;
+ rc = vpci_bar_add_handlers(d, dev);
+ if ( rc )
+ return rc;
#endif
+
+ return pci_add_virtual_device(d, dev);
}
/* Notify vPCI that device is de-assigned from guest. */
int vpci_deassign_device(struct domain *d, const struct pci_dev *dev)
{
+ int rc;
+
/* It only makes sense to de-assign from hwdom or guest domain. */
if ( is_system_domain(d) || !has_vpci(d) )
return 0;
+ rc = pci_remove_virtual_device(d, dev);
+ if ( rc )
+ return rc;
+
#ifdef CONFIG_HAS_VPCI_GUEST_SUPPORT
return vpci_bar_remove_handlers(d, dev);
#else
diff --git a/xen/include/xen/pci.h b/xen/include/xen/pci.h
index 2b2dfb6f1b49..35ae1d093921 100644
--- a/xen/include/xen/pci.h
+++ b/xen/include/xen/pci.h
@@ -136,6 +136,22 @@ struct pci_dev {
struct vpci *vpci;
};
+struct vpci_dev {
+ struct list_head list;
+ /* Physical PCI device this virtual device is connected to. */
+ const struct pci_dev *pdev;
+ /* Virtual SBDF of the device. */
+ const union {
+ struct {
+ uint8_t devfn;
+ uint8_t bus;
+ uint16_t seg;
+ };
+ pci_sbdf_t sbdf;
+ };
+ struct domain *domain;
+};
+
#define for_each_pdev(domain, pdev) \
list_for_each_entry(pdev, &(domain)->pdev_list, domain_list)
@@ -165,7 +181,9 @@ int pci_add_segment(u16 seg);
const unsigned long *pci_get_ro_map(u16 seg);
int pci_add_device(u16 seg, u8 bus, u8 devfn,
const struct pci_dev_info *, nodeid_t node);
+int pci_add_virtual_device(struct domain *d, const struct pci_dev *pdev);
int pci_remove_device(u16 seg, u8 bus, u8 devfn);
+int pci_remove_virtual_device(struct domain *d, const struct pci_dev *pdev);
int pci_ro_device(int seg, int bus, int devfn);
int pci_hide_device(unsigned int seg, unsigned int bus, unsigned int devfn);
struct pci_dev *pci_get_pdev(int seg, int bus, int devfn);
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 28146ee404e6..d304c7ebe766 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -444,6 +444,12 @@ struct domain
#ifdef CONFIG_HAS_PCI
struct list_head pdev_list;
+ struct list_head vdev_list;
+ /*
+ * Current device number used by the virtual PCI bus topology
+ * to assign a unique SBDF to a passed through virtual PCI device.
+ */
+ int vpci_dev_next;
#endif
#ifdef CONFIG_HAS_PASSTHROUGH
--
2.25.1
